Grinding machine



Feb. 25, 1936. s. EINSTEIN El AL 2,032,269

GRINDING MACHINE Original Filed June 28, 1929 ll Sheets-Sheet 1 Feb. 25, 1936. s. EINSTEIN ET AL 2,032,269

GRINDING MACHINE Original Filed June 28, 1929 ll Sheets-Sheet 2 fad 29/7170 Feb. 25, 1936.

S. EINSTEIN ET AL GRINDING MACHINE Original Filed June 28, 1

929 ll Sheets-Sheet 3 abkmmq Feb. 25, 1936. s. EINSTEIN El AL GRINDING MACHINE Original Filed June 28, 1929 ll Sheets-Sheet 5 7 W w. 0 1 B. M. Z L j r J M M w T (M i I ,M W ///////7///7/ iii 1.. W m W m a a v 4 r w \M 1 ,Ya/ a I a 4 i w ii, 7 a a in w v W 1 EINSTEIN ET AL 2,032,269

GRINDING MACHINE Original Filed June 28, 1929 ll Sheets-Sheet 6 Feb. 25, 1936. s. EINSTEIN ET AL GRINDING MACHINE ll Shets-Sheet 8 Original Filed June 28, 1929 F 25, 1936. s. EINSTEIN EI AL 2,032,269

GRINDING MACHINE Original Filed June 28, 1929 ll Sheets-Sheet 9 Feb. 25, 1936. s. EINSTEIN r:r AL

GRINDING MACHINE Original Filed June 28, 1929 ll Sheets$heet 10 FIIIII 1936- s. EINSTEIN ET AL 2,032,269

GRINDING MACHINE Original Filed June 28, 1929 ll Sheets-Sheet l1 Patented Feb. 25, 1936- iuurrso STATES [PATENT OFFICE" GRINDING MACHINE Application June 28 1929, Serial No. 374,558 Renewed October 25, 1932 20 Claims.

In the commercial generation of internal surfaces in the past it has been customary to position the work piece by suitable clamps, chucks or other members definitely engaging prescribed portions of the exterior of a work piece to hold the work in position during grinding.

The grinding has then been effected either by a rotation of the chuck or fixture in which the work is mounted or by. imparting a planetary movement to the grinding member itself. In either event errors as to size, concentricity and the like would occur and the production delays in this respect have necessarily been large as respects the limits of accuracy prescribed in through grinding due to the fact that accuracy of the final product has been dependent entirely upon the relationship of the various parts of the machine and any play in bearings, inaccuracy of engagement of the work positioning members and the like has been either reproduced or magnified in the finished product.

Furthermore, it has been hitherto found impossible, in prior art machines, to replace a ground work piece in the same position in which it was previously held, in the event that it was desired to perform a further grinding operation thereon (as when the work piece is undersize), and similarly it has been impossible to transfer work satisfactorily from one machine to another for the performance of subsequent grinding operations such as roughing and finishing, due to the inability to reinsert the work in the same or a similar machine in the position previously occupied with the axis of the surface being ground concentric to its axis of rotation, so that the grinding could be correspondingly continued.

As a result of these difiicult-ies, prior art internal grinding machines have necessarily been, in general, a compromise between roughing and finishing machines, since both operations had to be performed by the same machine and same grinding wheel. The customary practice has been to retrue the wheel between these two types of operation so that one or more trueings and consequent loss of grinding time were required in connection with every work piece.

It is an object of the present invention to eliminate these difliculties experienced with prior art mechanisms and to provide a machine of maximum accuracy in the production or generation of interior surfaces on a work piece.

- A further object of the present invention is the provision of a machine in which the manner of supporting the work piece will make it possible at any time to remove the work piece and reinsert it in the same or a similar machine in the exact corresponding position which it previously occupied, so that additional grinding or polishing operations may be subsequently performed in either the same or a different machine by the-use I of a proper grade of grinding wheel for that par-' ticular operation.

A further object of the invention is the provision of an improved grinder for the generation of internal surfaces on tubular or like work pieces 10 which shall be automatic in operation and which will reduce to a minimum the non-grinding time per production hour.

A further object of the invention is the prov vision of a machine of universal adaptability 15 which will produce an internal surface concentric to the finest degree of measurement with a preformed outer surface of the work and which may be quickly and easily adjusted to generate either cylindrical surfaces, tapered or conical sur 20 faces, or other surfaces of revolution, asmay be desired. 7

Further objects of the invention include the provision of novel control mechanism for the automatic functioning of the machine, the deter-' mination and control of size of the finished article and improvement in the several structural features of grinding or the like automatic machine details as will be readily apparent by reference to the following detailed description considered 30 in conjunction with the accompanying drawings, and it will be understood that we may make any modification in the specific structural details hereinafter disclosed, or in the combination, arrangement or operation of the machine within the 35 scope of the appended claims, without departing from or exceeding the spirit of the invention.

To facilitate an understanding of the invention there has been illustrated in the accompanying drawings one physical embodiment of the generic 40 principles thereof, in which:

Figure 1 is a front elevation of a machine constructed in accordance with and embodying the principles of the present invention.

Figure 2 is a plan view thereof. 45

Figure 3 is a fragmentary enlarged sectional view along the line 3-3 of Figure 1 illustrating the position of the work piece within the machine and the structure for introducing, supporting and removing such work pieces.

Figure 4 is a transverse sectional view along the line 4-4 of Figure 3.

Figure 5 is a vertical section through the size determining mechanism along the line 5-5 of Figure 4. 55

Figure 6 is a vertical section along the line 6--6 of Figure 5.

Figure 7 is a section along the line 1--'| of Figure 4, illustrating a portion of the control mechanism for the workv size determinator.

Figure 8 is a fragmentary section along the line 8-8 of Figure 7.

Figure 9 is a vertical section through the ejecting mechanism and associated parts along the lines 9-9 of Figure 4 and Figure 7.

Figure 10 is a section through one of the control mechanisms along the line I 0-! 0 of Figure 9.

Figure 11 is a similar sectional view along the line H-ll of Figure 9.

Figure 12 isa section through the ejector shaft and associate control parts along the line l2-l2 of Figure 9. I

Figure 13 is a vertical section through the regulating wheel drive mechanism along the line I3-l3 of Figure 1.

Figure 14 is a front view of the electrical cir cuit control mechanism with the cover plate therefor removed.

Figure 15 is a vertical section therethrough, along the lines iii-I5 of Figures 1 and 14.

Figure 16 is a section through the .hydraulic control valve and associated parts for regulation of the reciprocation of the table along the line iii-l6 of Figure 15.

Figure 17 is a similar section of the ejector control valve along the line |'Il'l of Figure 15.

Figure 18 is a transverse section through the bed of the machine along the line I8--I8 of Figure 1 illustrating the mechanism for controlling the relative feed of work and grinding wheel.

Figure 19 is a vertical section through said mechanism along the line l9-I9 of Figure 18.

Figure 20 is a section through the cam actuate ing cylinder and associated parts along the line 20-20 of Figure 19.

Figure 21 is a fragmentary section of the automatic compensator mechanismalong the line 2l--2l of Figure 18.

Figure 22. is a fragmentary section through the automatic coolant flow controlling valve along the line 22-22 of Figure 2.

Figure 23 is a detail section of the ejector dog along the line 2323 of Figure 1.

Figure 24 is a diagrammatic view illustrating the several inter-connected electrical and hydraulic mechanisms for complete automatic operation of the machine.

Figure 25 is a diagram indicating by suitable arrows the full directional movement imparted to the respective parts or units of the machine, and

Figure 26 is a perspective View of the entire machine showing the hydraulic control system in solid lines, and the rest of the parts in phantom.

The general construction and operation of our improved machine will be best understood by reference to Figures 1 to 4, inclusive, of the drawmgs.

From these it will be noted that in the embodiment here chosen for purposes of illustration, it comprises primarily a main bed 30, having ways 3| at one side and a lower set of ways 32 at the opposite side. Mounted on the ways 3| is the slide or carriage 33 bearing a drive motor 34, and a jack shaft 35 for transmitting power to the grinding wheel spindle 36 provided with a small diameter or internal grinding wheel 31.

The spindle 3B is mounted on carriage 33 for rotation but held against endwise movement. The desired slight reciprocation for the wheel 31 for breaking up grinding lines and traversing said wheel over the surface of the work is imparted to the grinding wheel carriage by a suitable hydraulically actuated piston 38 movable in 9. cylinder 39 carried by the bed. Reversal of direction of actuation of the piston is efiected by reversing lever 40 carried on the front of the grinder control box 4|. This lever cooperates with and is actuated by the adjustable dogs 42 mounted 'on the forward face of the carriage 33. By this. construction, a normal reciprocation of an amount predetermined by the adjustment of the dogs is continuously applied to the grinding wheelduring actuation of the machine except at such times as lever 40 is manually shifted to an intermediate or neutral position.

Mounted on the ways 32 is the reciprocating table 43 suitably coupled by rod Ma, Fig. 16, with piston I35 movable in a cylinder I36 carried by the bed. This piston is hydraulically operated in its cylinder for moving the table toward or from the grinding wheel. v

The starting, stopping and reversing of the piston and thus of the table is effected by suitsupporting and controlling member carried thereby, from disengaged or in operative position (as shown in Figures 1 and 2, for example), to a position in which the grinding wheel 31 will be operatively disposed within the internal bore of a, work piece 44, as shown in Figure 4.

In initiating the grinding operation as well as in withdrawing the parts from grinding relation. the grinding wheel is first disposed within the internal bore oi the Work and then subsequently the work is fed radially into the grin-ding wheel for desired stock removal to avoid a stock removal effected during the axial movement of the work and wheel into inter-engaged position which imposes an undue amount of work on one edge or portion of the grinding wheel. To facilitate this manner of engagement and relative feeding of grinding wheel, the work table 43 is preferably formed with the dove-tailed guide 45 for the supplemental table or cross-slide 46 which carries the work holding member, and the size determining mechanism.

The cross feed movement here required for the grinding operation is normally slight and is attained through the use of a suitably actuated cam 41 carried by the slide 43 and engaging a cam follower 48, best shown in Figure 18.

' On the supplemental slide 46 is a swivel table 49, Figs. 1 and 13, the latter having the worm rack 56, Fig. 1, engageable by adjusting screw 5| by which. the supplemental table is set at any desired angle to the ways 3| and 32.

A micrometer scale 52 facilitates determination of the angle of adjustment of the swivel table 49. The swivel table 49 has the bracket 53, Fig. 4, containing suitable anti-friction bearings 54 for the regulating wheel spindle 55 which supports a regulating wheel 56 preferably constructed of suitable abrasive or frictional material, said wheel engaging the external surface of the work piece 44 and by its rotation controlling the rate of rotation of said work piece. Power to rotate the regulating wheel spindle and regulating wheel at a slow rate of speed is applied to worm gear 51 on the spindle by a worm 58 on a vertical shaft 59 journaled in the lower portion of the bearing bracket 53.

" ing with pinion 63. Drive shaft 66 is primarily journaled in the bearing bracket 68 on the under side of the table 43 and is provided with the stepped pulley 69 for suitable application of driving power thereto. By this construction, it will be noted that the swivel table 49 may be inclined as des'red without affecting the drive to the regulating wheel, and, at the same time, slide 46 may be given its desired back and forth movement with flange 60 operating in a suitable slot in the bed, with the bushing 95 and. its drive pinion 61 moving freely lengthwise of the splined portion of shaft 66. Suitable mechanism may be employed for shifting the slide 46 and parts carried thereby in a rearward or retracted direction, said mechanism, as shown in the present instance, comprising a cylinder 10 secured to or formed in table 43 and containing a piston H having integral therewith a. stud 12 bearing against the dependent flange 60. This piston is intended to be suitably hydraulically actuated for rearward shifting of the cross-slide while permitting of free rotation of the swivel table. The hydraulic pressure or volumetric urge in the cylinder 10 is of such nature as to yield and permit of forward movement of the cross-slide under the urge of actuating cam 41 previously referred to.

Disposed on the swivel table 49, in suitable relation to the regulat ng wheel, is a work rest bracket 13, Fig. 3, bearing a work rest blade 14. In normal operation of the machine, bracket 13 is so adjusted with respect to the regulating wheel 56 as to be spaced therefrom an amount greater than half the diameter of the work piece 44 to be operated upon and the blade itself is provided with an angled top.

Th s arrangement of parts provides a trough having two points of contact with the periphery of the work piece, to engage and support said work piece properly for operation of the grinding wheel thereon. That the work may be best supported and retained within this trough, use may be made of a friction pressure roll 15 disposed to urge the work toward the regulating wheel and downwardly in the supporting trough, as indicated in Figure 3 of the drawings.

The structural details of this'pressure roll unit are particularly illustrated in Figure 9 of the drawings, from which it will be noted that a bracket 16 is adjustably secured on the swivel table 49 by the bolts 16', Fig. 4. This bracket has bearings for the bushing TI on which is secured the yoke 18 provided with anti-friction bearings 19 for the spindle of pressure roll 75. Thepressure roll, it will be noted, has its axis permanently d sposed at an angle to the horizontal or general plane of the machine.

In the normal operation of the machine, the regulating wheel is rotated in a counter-clockwise direction, as viewed in Figure 3, shOWing a face view of the regulating wheel. As so rotated, its cuter friction surface engages the outer surface of work piece 44, the two being geared together to rotate in unison, with the work moving in a clockwise direction or with its front surface moving upwardly. Pressure roll 15 is mounted for free rotation on the bearings 19, holding the work firmly against the regulating wheel while, at

the same time, the angular disposition of this pressure roll causes it to exert an axial component or thrust against the work, holding the work in position against the back plate 00a, Fig. 4.

The surface of the pressure roll is preferably covered with leather, rubber or other yieldable material and may-be either positivelyor frictionally rotated while in engagement with the work piece when the latter is in position within the throat to hold same in position on the work rest and in driving engagement with the regulating wheel.

As illustrated, sleeve I1 is provided with a collar 81, Fig. 9, having a projecting arm 82, Figs. 4 and 12, which extends into a cylindrical passage 83 of bracket 04 where it is engaged by spring-pressed plunger 85, the latter serving to actuate the arm downwardly and thus rock sleeve 11 to urge the pressure roll inwardly against the work.

The yoke 10, in addition to supporting the pressure roll, is provided with abearing cup plate 80, Fig. 9, having a stud 81 loosely supporting the pinion 88 which meshes with an actuating rack segment latter extending through sleeve 11. The pinion 88 has an arm 9| coupled with an oscillatory ejector arm 92 for rocking movement of said arm in response to rotation of said pinion.

. Arm 92 terminates in a head 93, having pivoted therein the dog or finger 94 (see Fig. 23) provided with an inclined or cam surface 95, permitting same to snap down past the work. Spring 96 forces said dog outwardly after it has passed the upper edge of the work during downward and inward swinging movement of said ejector arm 92, causing shoulder 91 of the dog to engage the inner face of the work piece. On the upward and outward movement of said arm, the dog 94 will consequently lift the work up out of the space between the regulating wheel and pressure roll and discharge same from the machine. During the upward swinging movement around the roll 15, said work piece will engage a latch member or detent 9B of the work piece 44 to release an unground piece of work from the chute or hopper 99, Fig. 3, and this lat ter unground work piece will be caused by gravity to drop into a position on work rest -14 for subsequent grinding. The swinging movement of the ejector is controlled by a pinion I00, Fig. 12, secured on shaft 90 and meshing with the rack portion |0| of piston I02 movable in cylinder I03 formed in the lower portion of bracket 84. As the piston is moved toward the right, as seen in Fig.

12, a ball I04 will be raised from a groove I05 of the piston I02, said ball bearing against and lifting arm 82 and consequently rocking yoke 18 forwardly or away from the work to release the work from the pressure of roller 15. This movement of the piston, through pinion, I00, also rocks segment 89 forwardly, which, through pinion 88, swings the ejector arm 92 downward. Reverse move-.

ment of the piston raises the ejector arm, .continuing to a position where ball I04 will again drop into groove I05. The timing of the machine is such that before this occurs the unground work piece will be in operative position, when release of arm 02 permits spring-pressed plunger to function thereagainst, the latter swinging the pressure roll into proper engagement with the unground work piece then in operative position within the machine.

In order that the machine may be fully automatic in operation and may produce work pieces 89 secured on rock shaft 90. the

I therewith controls for the discharge of completed u ch work pieces and insertion of unground work pieces. A suitable form of size controlling mechanism is particularly illustrated Figures 4, 5 and 6 .of the drawings. It comprises bracket plate I06, secured to bracket 16, and for in and out adjustment relative thereto, use is made of the bolt and slot connection I01 and micrometer screws I08. Pivoted to this bracket plate is a housing I09, frictionally held in adjusted position as by the nut and spring plate cup structure IIO, facilitating minute degrees of variation in posi tion of the housing. This housing has longitudinally journaled therein, the shaft III provided with an arm I I2 carrying a diamond point or the like II3 (see Fig. 3) for engagement with the inner surface of the work piece. In use, this member is adjusted into such position with respect to the surface of the regulating wheel which exteriorly engages the work that when the inner surface of the work has been ground away a prescribed amount, the point H3 will just ride over the work in an arcuate path tangent to the inner generated surface. At the inception of the grinding operation. shaft III is so rocked that the arm H2 and point II3 will be disposed in an upward or above center position, with spring II4 compressed. by plunger II6, the latter engaging an elongated pinion II8 on shaft III. Expansion of the spring tends to move the plunger upwardly, thus rocking shaft III to cause the point II3 to swing downwardly past the center of the work, interengagement of the point and surface of the work preventing such swinging movement until the work has been ground down to the desired size.

Shaft III, is provided with a cam II9, Fig. 5, which serves, on the rotation aforesaid, to lift contact I20 of switch mechanism I2l, closing the electrical control circuit I22, Fig. 24, to initiate movement of regulating wheel or work supporting unit rearwardly or away from grinding position, as will hereinafter appear.

This also initiates a movement of the work supporting unit longitudinally of the bed or in an axial direction away from the grinding wheel until grinding wheel and work are disengaged. As the tabie 43 carrying the work supporting unit retracted longitudinally of the bed, the adjustable dog I23 thereon contacts with a trip arm I2, which, through link I25, transmits motion to an interengaged series of control levers, solenoid members and the like in the control box of Figures 14 to 17. The series of controls then successively function, as will be pointed out, to actuate the ejector mechanism the work engaging position previously described, and this movement of the ejector in turn controls electrical circuits for reversely rocking the ejector to withdraw the completed work piece, for mechanically withdrawing the feeler or sizing member from within the work prior to ejection of the work piece, for thereafter restoring said feeler member to a raised position and for reinserting said feeler within theungrc-und work piece. The carriage movement is subsequently automatically reversed to bring the unground work piece into telescoping relation with the grinding wheel. On

this reverse movement the second table dog I26 reversely actuates link I25 and the control mechanism coupled therewith, to feed the work piece radially into the grinding wheel, when theprescribed cycle of operation will be repeated.

The foregoing cycle of operations is diagrammatically illustrated in Figures 24 and '25 of the drawings and will be generally described in conjunction therewith, subsequent reference being made to individual sectional views for the exact mechanical or other structural details of the particular mechanism here illustrated for carrying into effect the results there indicated.

In Figure 24,. I21 designates a lead of the general electric circuit and I28 the opposite or return lead thereof. The several electrical circuits have been' indicated in full lines together with diagrammatic views of, the several hydraulically actuacle piston members and control valves therefor, while the hydraulic circuits for actuation of the various mechanical elements of the machine have been indicated by dotted lines.

As above stated, closing of switch or circuit controlling member I26, by oscillation of the sizing feeler, completes the circuit I22 through solenoid I29.

I3I (see also Fig. 20) to the left. This brings the low portion of cam 41 opposite roller 48, when the constantly existing pressure in cylinder I0 (see Figure 13) will move the supplemental table 46 rearwardly, thereby withdrawing the work piece radially from the grinding wheel. same time, member I20 also closes a circuit through solenoid I32, shifting valve I33 to admit pressure to cylinder E36, actuating piston I35 to the left, as shown in Figures 16 and 24, to move 1 the work supporting unit 43 longitudinally into retracted position on the bed. This movement causes table dog I23 to engage and rock the arm I24, thereby closing switch or contact I38 of circuit I39, energizing solenoid I40. -This solenoid shifts valve i4I, admitting pressure to actuate piston I02 to the right (see Fig. 12), thus swinging ejector downwardly into engagement with the work piece. As the ejector arm swings downwardly, a cam I52, Fig. 9, on shaft actuates a circuit closer I43 for a circuit I44 through solenoid I45, thereby reversing the valve HI and thus the direction of movement of the piston W2 and of the ejector arm 92. During the reversing movement of the arm 92, a pawl I46, Fig. 10, carried by a cam I41 on the shaft 90 actuates the circuit completing member I48, thereby closing a circuit I49 through the solenoid N30. The pawl I46 is suitably constructed to prevent actuation of said member I48 by said pawl during the initial counterclockwise movement of the shaft 90. The solenoid I50 then reverses the valve I33 and accordingly the direction of movement of the table controlling piston I35, thereby procuring a longitudinal movement of the table 43 to the right toward the grinding wheel. During this movement, the dog I26 reversely actuates the member I24 to close a contact I5I of a circuit I52 through a solenoid I53. Energization of this solenoid I53 reversely shifts the valve I30 reversing the piston I3I to cause a forward feeding movement of the cross slide 46 to bring the unground workpiece radially intoengagement with the grinding wheel.

The cycle of operation is then repeated and con-' This shifts valve I30, actuating piston At the latter carrying at its upper end a. rock arm I68 coupled by link I60 with an arm I6I, Fig. 4, on shaft I62. As shaft 90 is rocked, under the iniiuence of its controlling piston, cam I54 forces plunger. I56 outwardly, rocking shaft I58 and causing a clockwise oscillation of member I62 and the arms I63 and I64, Fig. 5, secured thereto. Arm I63 has a shifter pin I65 riding in groove I66 of the spindle II I, and serves on actuation to retract said spindle and the feeler point carried thereby out of the plane of the work. As this retracting movement is effected, arm I64 is brought down upon plunger II6 to reversely rock the spindle III. The high point or portion of cam I54 serves to hold the parts in the position just described until the movements of the ejector arm have withdrawn the completed work piece from the work support, andcaused an unground work piece to feed down from the hopper. The return movement of the cam allows plunger I56 to ride back into the position shown in Fig. 7, in which the rock arm I59 is released. The link I60 is then returned to original position by a spring I61, thereby rocking the arms I63 and I 64 to the position of Fig. 4; return of the arm I 63 advances the spindle III to reposition the gauging point II3 within the bore of the work piece, and return of the arm I64 releases the plunger II6 to permit expansion of the actuating spring II4, thereby bringing the point into engagement with the internal bore of an unground work piece and urging said point against the surface of the work piece in a direction opposite to the direction-of rotation of said work piece. When the parts have been restored to work engaging position, the grinding operation is begun by an axial and radial advance of the work piece into engagement with the grinding wheel, as above pointed out. The grinding wheel itself is continuously rotated and has a slight reciprocating movement imparted thereto, so that it is merely necessary to move the work toward the grinding wheel and suitably feed same inwardly.

Details of the mechanism illustrated for this purpose are shown in Figures 18 to 21 inclusive. Carriage 43 supports the cross-slide 46,- in which is swiveled the position adjusting screw I68, which may be suitably, manually actuated from the front of the machine, or automatically actuated by the compensator contained within the bed of the machine. This screw is in threaded engagement with the slidably mounted elongated nut I69 carrying a roller 48, which rides on the surface of cam 41. Cam 41 is secured to or integral with sleeve I10, oscillatably supported in carriage 43 by pin I1I. The sleeve has a depending arm I12, Fig. 20, bifurcated as at I13 to engage the block I14 swiveled on reciprocating piston I3I. When the solenoid I53 is energized, it shifts valve I30 so that a suitable fluid pressure medium will enter the left-hand end of the cylinder, urging the piston to the right to rock cam 41 to the position shown in Figure 18. In this movement. the cam will tend to press roller 40 and thus the nut I69 forwardly, moving the fcross-slide 46 to the left (Fig. 18) or forwardly,

causing radial feeding of the work against the grinding wheel. To secure additional feeding movement other than that thus automatically effected, it is merely necessary to rotate screw I 68 manually. This forward or feeding movement is in opposition to pressure piston 1I, previously referred to, which normally tends to hold the entire unit in a rearward or retracted position.

with a ratchet As the grinding wheel wears down during the operation on successive work pieces, it is necessary. to compensate for such wear so that all pieces may be ground to a standard internal diameter. This, of course, may be effected manually but it is preferable that'the compensation be cared for automatically and the mechanism for accomplishment of this is particularly illustrated in Figures 18 and 21. Depending from the slide 43 is a bracket member I15 supporting the vertical shaft I 16 having at its upper end the bevel gear I11 meshing with a similar gear I18 rotatable in the anti-friction bearings I18 supported by a portion of the slide 43, said gear having a sleeve portion I80 splined on the rear end of screw I68, so that the screw may slide freely therethrough during movement of cross slide 46. Shaft I16 has rotatably mounted on the lower portion thereof a disc I8I, having integral therewith a spur gear I82 in permanent mesh with gear I83 of sleeve I84, which has a second gear :8? meshing with the rack I86, Fig. 19, on piston As the piston reciprocates, the spur gear I83 I85 will be rotated, imparting a corresponding rotation to disc I 8| loose on the shaft I16. The disc I8I has pivoted thereto a pawl I86a normally urged by a spring I81 into engagement I88 secured to the shaft I16, movement of said pawl tending to rotate the said ratchet and thus the shaft I16 in a counterclockwise direction as the disc I 8| rotates in the same direction. During the reverse or clockwise movement of the disc I8I, the pawl rides idly over the ratchet without actuating the same.

A knockout screw I89 serves at a given point in the rotation of the disc to engage the outer end of the pawl I86a, moving same away from the ratchet I88 so that shaft I16, when the parts" are in retracted position, may rotate freely as the screw I68 is adjusted. As the piston I3I moves rearwardly urging the cross-slide 46 forward, disc I8I will be rotated in a clockwise direction. A greater or less amount of rotation will be given the disc I8 I. depending upon the distance which the piston I3I travels in urging the crossslide 46 forward, before a suflicient amount of stock, as determined by the feeler, has been removed from the work piece. During this movement, pawl I 86a will be shifted away from the knockout screw I 89 and will start to ride over the teeth of ratchet I88. If but a slight movement is given to the disc, the pawl will contact with the ratchet tooth and ride along the face thereof without slipping down behind one of the teeth and will consequently move back to initial position without actuation of the ratchet.

On the other hand, if the grinding wheel has Worn down to-an extent requiring a relatively large movement of the piston and consequentially a relatively large rotation of the disc bearing the pawl I 86a, the reverse movement of cross slide 46 then will cause the pawl to interengage with the ratchet and on return movement, will slightly rotate said ratchet.

This movement is transmitted through shaft I16 and the intermeshing bevel gears I11 and I18 to screw I68, slightly turning this screw in nut I69 to compensate for the wear which has taken place on the grinding wheel. In this manner, an entirely mechanical, automatically operated mechanism is provided in which the movement of the cross slide control cam is automatically effective to compensate for wheel wear so that the machine can run indefinitely without the necessity for manual adjustment and yet with the desired size of work pieces attainedand the necessary movements of the cross-slide secured by a non-adjustable or constant throw cam member.

The main control unit of the work supporting unit of the machine has been illustrated in Figures 14 to 17 inclusive. This unit includes the cylinder I36 for the table controlling piston I35,

the control valve therefor, the control valve for the work ejector unit and inter-connected mechanisms for mechanically and electrically shifting the valves in question, as well as certain additional related electrical control units.

Link I25 on the front of the machine is pivoted to rock arm I90 (see Fig. 15) of the control unit, which is secured to rock shaft I 9| to which is secured the shifter I92, the latter having an enlarged aperture I93 surrounding shaft I94 of the manual control lever I95. This lever has a depending furcated yoke member I96 engaging pin I91 carried by shifter I92. It will thus be seen that member I92 may be moved through actuation of link I25 on arm I90 or by action of yoke I96 on pin I91 as manually effected by rocking of handle I95.

In addition, there is coupled to member I92 a pair of links I98 and I99 respectively secured to cores 200 and 20I of the solenoids I32 and I50 respectively. By this arrangement the lever I95 may be turned to shift the parts from neutral position, as indicated in Figure 14, to actuate the controlling valve (for table 43) and thus move said table in either direction. The table will then move until table dog I23 or I 26 contacts with rock arm I24.

Inasmuch as there is no load and fire mechanism connected with the rock arm, its link and associated parts will cause a movement of the parts again into merely neutral position while a reversal of the valve is efiected only through actuation of one or the other of the solenoids I32 or I50, above referred to in connection with the description of the general controls of the machine particularly illustrated in Figure 24.

Actuation of either of these solenoids will rock member I92 a sufficient amount to act through pin I91 and rock arm 202 to shift table valve I33, this shifting being effected through a rock shaft 203 and an arm 204 associated therewith, thereby to actuate the table 43 in the selected direction. The rock yoke I91 is additionally provided with the lateral wings 205 and 205 for actuation of the one way switches I38 and I5I.

The mechanism for actuating the switch I38, as shown in Fig. 14, comprises an intermediately pivoted plate 201 having an actuable projection 208 for engagement by the tip of the adjacent wing 205 as it oscillates past the projection in either direction and the interengagement oi: the parts serves to rock plate 201. On upward movement of the wing the plate 201 idly rocks against spring pressed plunger 209 without affecting the switch. On movement in a reverse direction toward neutral position, however. as the table control valve is moved into neutral position, stopping movement of the table, the oscillation of the plate causes it to contact with the associated switch plunger 2I0 serving to close switch I38. The wing 206 cooperates with similar mechanism for actuating the switch I5I. It will thus be seen that as the table is brought to a stop at one limit of its movement, as automatically effected by the table dogs, the cross feed of the slide will be initiated by closing of the switch I5I to shift the valve I whichcontrols the cross feed. At the other limit of movement of the table 43, the ejector arm will be caused to function by the closing of a switch I38 in the manner above pointed out.

Loosely mounted on shaft 203 is the sleeve 2 tov which is secured at one end a rock arm 2I2 and at the opposite end a shift yoke 2I5. The rock arm H2 is coupled by links 2I3 and 2 with the sliding cores of solenoids I40 and I45, while shift yoke 2I5 is coupled with the reversing valve I4I ofthe ejector. This valve is shown in detail in Figure 1'1 and it will be noted is not designed to have a neutral position and at all times directs the current hydraulic actuating medium into one end or the other in the cylinder I03 for piston I02 controlling the ejector.

As the table is brought to a stop in its rearward movement, switch I38 functions energizing solenoid I40, while on rotation of the ejector, a contact is completed through switch I43 energizing solenoid' I45 to reverse the valve and cause the ejector to lift out and withdraw the finished work piece, the pressure in the cylinder I03 positively holding the ejector in raised or inoperative position until the valve therefor is again reversed.

The cycle of operation That the complete automatic functioning of the machine may be best understood, reference is made to Figure 25 of the drawings, graphically is supplied to the machine in a suitable manner as by an electrical motor for actuation ofpump 2I6, and motor 34 is also suitably energized to impart driving rotation to spindle 33, the pump motor or prime mover being also preferably utilized to drive shaft. j

Grinding wheel 31 rotates at a high rate of speed in the direction of the arrow shown thereon in Figure 25, while regulating wheel turns at a slow rate of speed in the direction of its arrow. Movement of handle 40, Fig. 1, starts hydraulic oscillation by suitable shifting of valve 2", this reciprocation being continued by action of the dogs 42 on said handle, the movement of the grinding wheel thus being a constant back and forth one, as indicated by the arrows 2" of Figure 25.

An initial work piece 44 having been placed in position on the machine on work rest 14 and pressed by roller 15 against the regulating wheel 55, rotation is imparted to the work piece by the regulating wheel. Handle I95, Fig. 1, is then shifted to cause movement of the carriage 43 toward the grinding wheel, which movement continues until the grinding wheel is within the bore of the work, when contact of dog I25 with rock arm I24 stops the inward movement of the slide indicated by arrow 2I9. At this point, switch I5I is closed, causing the complete slide unit, comprising regulating wheel, work rest and pressure roll with size controlling member, to move forward in the direction indicated by arrow 220 until grinding to the prescribed depth has been performed. At this point, sizer II2 rotates, as indicated by arrow 222. At the same time the carriage is rapidly retracted radially in the direction of the reversed arrow 223, and also axially in the direction of the arrow 223a. As the carriage is retracted, the necessary circuits are completed, successively retracting the pressure roller causing a downward and reverse upward swinging of the ejector arm to remove the finished work piece and allow an unground one to move into position on rest 14. The machine is then automatically reversed, to present the succeeding work piece to the action of the grinding wheel, and the above operation is repeated. For most eilicient operation, it is desirable that a suit able coolant be supplied to the work during grinding, this being eifected through pipe 224, and, to avoid waste of coolant or unnecessary flow during removal of work pieces, a suitable poppet valve such as shown in Figure 22 is utilized, this valve 225 having a stem 226 adapted to contact with an abutment 22'! on carriage 43 so that, as the work is moved into position for engagement by the grinding wheel, the valve will be opened to allow a flow of coolant. An axial withdrawal of the work piece from the grinding wheel operates to shut off the supply of coolant by retraction of the abutment 221 from engagement with the valve.

In the foregoing description of the construction and operation of our improved hole generating machine, the advantages thereof should be readily apparent and it will be seen that we have provided an eificient machine in which a work piece, preferably preformed or accurately shaped as to its outer surface, may be readily inserted radially as distinguished from the usual axial introduction of work pieces into the well-known chucks of internal grinding machines. The present machine has a much greater factor of safety to the operator in introduction and removal of work in the above manner. It will further be noted that the work when introduced is in no wise dependent on center chucks or similar holding devices for its position, but that its accurate location within the machine is controlled by the engagement of its preformed external surface with the surface of the regu ating wheel 56, which may be trued as by mechanism 228 so that said surface will at all times properly and accurately engage the work. Further support of the work is taken up by the rigid, non-adjusted and non-yielding work rest member. The position of the work is therefore dependent entirely upon its external surface which itself provides a progressive determinator for the location of the work and eliminates the errors previously experienced, due to play in various parts of a machine or inaccuracy of chucks or other gripping members.

It will further be noted that the angular relationship of the pressure roller serves to urge the work positively against the back plate 80, thus retaining it within the machine on the work rest, unaffected by the reciprocation imparted to the grinding wheel. By mounting of the grinding wheel and the drive therefor as a unit upon its own oscillatable slide, a more accurate and more desirable drive therefor is accomplished than has been possible with prior art mechanisms in which the grinding wheel is moved into and out of operative position, the latter movement necessitating a sliding of belts or the like relative to the prime mover or source of rotation therefor, while the confining of the movement of the grinding wheel solely to an axial adjustment for its reciprocation and eliminating any radial adjustment thereof, permits maximum accuracy of position of the grinding member at all times as respects the remainder of the machine.

Furthermore, by'tne separation of the several prime movements necessary for internal grinding, the high speed grinding spindle may be rigidly mounted and given a. slight reciprocation, while the work supporting unit which is more slowly rotated may be quickly moved into operatlve relation to the grinding wheel. By this construction, the vibration of the work is reduced to a minimum and by the slight necessary feeding movement in the direction of the grinding wheel, a most accurate operative relationship of the parts and thus an increased accuracy of the finished product is assured.

The foregoing are of marked utility for grinding, irrespective of the manner in which the work may be introduced, but the construction in question also particularly lends itself to an automatic introduction of the work such as here described in which, by reason of the radial introduction as distinguished from previous necessary practice of axial introduction of the work, only a relatively slight separation of work holder and grinding wheel is necessitated, while the automatic mechanism rapidly functions to remove the finished work piece and effect introduction of an unground work piece, thereby reducing the idle or non-grinding time of the machine and permitting of its recurrent or continuous cyclic operation as long as work pieces are supplied to the hopper thereof.

We claim:

1. In a machine for grinding hollow articles, the combination with a supporting member, of a work rest carried thereby for peripheral engagement with the work piece, a regulating member rotatably mounted on the support in opposition to the work rest for peripheral engagement with the work, means for rotating said member at a slow rate of speed to frictionally control the rotation of the work, a pressure roll in'opposition to the work rest and regulating member, means for urging the roll into engagement with a work piece, additional means for urging the pressure roll into released position, an ejector, and connections between the ejector and said additional means for actuating the ejector when the work is released.

2. In a machine for grinding hollow articles, the combination with a supporting member, of a work rest carried thereby for peripheral engagement with the work piece, a regulating member rotatably mounted on the support in opposition to the work rest for peripheral engagement with the work, means for rotating said member at a slow rate of speed frictionally to control the rotation of the work, a pressure roll in opposition to the work rest and regulating member, means for urging the roll into engagement with a work piece. additional means for urging the pressure roll into released position, an ejector, connections between the ejector and said additional means for actuating the ejector when the work is released, and an end stop member for the work, the pressure roll having its axis arranged at an angle to the axis of rotation of the work whereby when in engagement therewith it exerts a feed component urging the work against the stop.

3. In a machine for grinding hollow articles the combination with a supporting member, of a work rest carried thereby for peripheral engagement with the work piece, a regulating member rotatably mounted on the support in opposition to the work rest for peripheral engagement with the work, means for rotating said member at a slow rate of speed frictionally to control the rotation of the work, a pressure roll in opposition to the work rest and regulating member, means for urging the roll into engagement with a work piece, additional means for urging the pressure roll into released position, an ejector; connections between the ejector and said additional means for actuating the ejector when the w'ork is released, means for bodily shifting the work supporting unit, an electrical control circuit for said last means, a switch memher for the circuit' and means rendered effective by movement of the ejector for actuating said switch. f

4. An internal grinding-machine including a bed, a grinding wheel mounted thereon, hydrauhe means for imparting a constant limited reciprocation to thei grinding wheel on the bed, mechanical means for controlling said reciprocation. a afork holding unit movable longitudinally of the bed for presentation of work in operative relation to the grinding wheel and movable transversely pf the bed to feed the work against the grinding wheel, hydraulically actuable means for imparting said longitudinal and transverse feeding" movements to'the work supperting unit, means on the unit for supporting a work piece, and means for varying the position of said supporting means relative to the unit to vary the presentation of the work to the grinding wheel for a given movement of the unit.

'5. In a machine of the nature described the combination with a work supporting carriage having means for peripheral engagement with a work piece to support the same in grinding position while permitting ef radial removal therefrom, of a gaging member projectable into engagement with the interior of the work piece for determining the size thereof, an electric circuit, means for closing the circuit on predetermined movement of th(% gage, means operable by closing of said circnit for retracting the carriage to inoperative piosition, and additional means rendered operative by said retraction for successively withdrawing the gage from the work piece and ejecting the work piece radially from the supporting mechanism therefor.

6. In machine of the nature described, the combination with a work supporting carriage having means for peripheral engagement with a work piee to support the same in grinding position while permitting of radial removal there-" from, ofja. gaging member projectable into engagement with the interior of the work piece for" determining the SlZE thereof, an electric circuit, means for closing the circuit on predetermined movement of the gage, means operable by closing of said circuit for retracting the carriage to in operative position, an ejector, an additional means rendered operative by said retraction for successively withdrawing the gage from the work piece and actuating said ejector' for ejecting the work piece from the supporting mechanism therefor, and means rendered effective by movement of the ejector for reversely shifting said ejector and moving the gage into operative relation with a subsequent work piece; 7

'I. In a machine of the nature described the combination with a, work supporting carriage *having means for peripheral engagement with a work piece to support the same in grinding position whilei permitting of radial removal therefrom, of a gaging member projeetable into engagement with the interior of the work piece for determining the size thereof, an electric cir cuit, means for closing the circuit on predeter minedlf novement of the gage,-means operable by closing of said circuit for retracting the car riage t?) inoperative position, an ejector, an ad;-

aosaaeo ditional means rendered operative by said retraction for successively withdrawing the gage from .the work piece and actuating said ejector for ejecting thcfwork piece from the supporting mechanism therefor, means rendered effective by movement of the ejector for reversely shifting said ejector and moving the gage into operative relation with a subsequent work piece, and for initiating movement of the carriage and worle piece into operative grinding position.

8. In a machine of the character described the combination with a bed and a grinding wheei carried? thereby, of a work supporting unit mounted on the bed including a work rest amf opposed regulating wheel for peripheral engage ment with the exterior of the work, means for imparting relative axial movement to the grinding wheel and work supporting unit, means for imparting relative feeding movement to said parts, a gaging'device, connections between the gaging device and the feeding mechanism for stopping the feeding when the prescribed grinding has been performed, and control mechanism including a bracket, a bushing 'journaled in the bracket, a rock shaft journaled in the bushing, a yoke carried by the bushing and slidable therewith, a pressure roller carried by the yoke for exterior engagement with a work piece wheri'in position in engagement with the work rest and regulating wheel, means for urging the roller into engagement with the work, an ejector pivotally supported by the yoke, and means for shifting the yoke to disengage the roller from the work and for shifting the ejector relative to the yoke to remove the work piece from the machine.

9. In a machine of the character described the combination with a bed and a grinding wheel carried thereby, of a work supporting unit mounted on the bed including a work rest and opposed regulating wheel for peripheral engagement with the exterior of the work, means for imparting relative axial movement to the grinding wheel and work supporting mechanism, means for imparting relative feeding frnovement to said parts, a gaging device, connections between the gaging device and the feeding mechanism for stopping the feeding wherr the prescribed grinding has been performed? and control mechanism including a braeket a bushing journaled in the bracket, a rock shaft journaled in the bushing, a yoke carried by the bushing and slidable therewith, a pressure roller carried by the yoke for exterior engagement with a work piece when in position in engagement with the work rest and regulating wheel, means for urging the roller into engagement with the work, an ejector pivotally supported by the yoke, and means for shifting the yoke to disengage the roller from the work and for shifting the ejector relative to the yoke to remove the work piece from the machine, said means including a pinion associated with the ejector and a segment carried by the rock shaft for actuation of the pinion.

10. In a machine of the character described the combination with a bed and grinding wheel carried thereby, of; a work supporting nnit mounted on the bed including a work rest and opposed regulating wheel for peripheral engagement with the exterior of the work, means for imparting relative axial movement to the grinding wheel and work supporting frnechanism, means for imparting'relative feeding movement to said parts, a gaging device, connections between the gaging device and the feeding mechanism for stopping the feeding when the prejournaled in thabracket, a rock shaft journaled in the bushing, a yoke carried by the bushing 'and slidable therewith, a pressure roller carried by the yoke for exterior engagement with a work piece when in position in engagement with the the roller into engagement with the work, an ejector pivotally supported by the yoke, means for shifting the yoke to disengage the roller from the work, means for shifting the ejector -relative to the yoke to remove the work piece from the machine, and actuating means for oscillating the rock shaft to effect said shifting including a pinion on the shaft, and a shiftable rack for rotating the pinion.

' 11. In a machine of the character described the combination with a bed and grinding wheel carried thereby, of a work supporting unit mounted on the bed including a work rest and opposed regulating wheel for peripheral engagement with the exterior of the work, means for imparting relative axial movement to the grinding wheel and work supporting mechanism, means for imparting relative feeding movement to said parts, a gaging device, connections between the gaging device and the feeding mechanism for stopping the feeding when'the prescribed grinding has been performed, and control mechanism for the work including a bracket, a bushing journaled in the bracket, a rock shaft journaled in the bushing, a yoke carried by the bushing and slidable therewith, a pressure roller carried by the yoke for exterior engagementwith a work piece when in position in engagement with the work rest and regulating wheel, means for urging the roller into engagement with the work, an ejector pivotally supported by the yoke, means for shifting the yoke to disengage the roller from the work and for shifting the ejector relative to the yoke to remove the work piece from the machine, means for oscillating the rock shaft including a pinion on the shaft and a shiftable rack for rotating the pinion, a control arm on the bushing, and means associated therewith for shifting of the arm on initial movement of the bushing to disengage the roller from the work prior to operative engagement of the ejector with the work.

12. In a machine of the character described the combination with a bed and a grinding wheel carried thereby, of a work supporting unit mounted on the bed including a. work rest and an opposed regulating wheel for peripheral engagement with the exterior of the work, means for imparting relative axial movement to the grinding wheel and work supporting mechanism, means for imparting relative feeding movement to said parts, a gaging device, connections between the gaging device and the feeding mechanism for stopping the feeding when the prescribed grinding has been performed, a control mechanism including a bracket, a bushing journaled in the bracket, a rock shaft journaled in the bushing, a yoke carried by the bushing and chine, a cam member carried by the rock shaft and connections between the cam and gage for shifting the gage out of work engaging position prior to operation of the ejector.

13. In a machine of the character described the combination with a bed and a grinding wheel I carried thereby, of a work supporting unit mountwork rest and regulating wheel, means for urging ed on the bed including a work rest and an opposed regulating wheel for peripheral engagement with the exterior of the work, means for imparting relative axial movement to the grinding wheel and work supporting mechanism, means for imparting relative feeding movement to said parts, a, gaging device, connections between the gaging device and the feeding mechanism forstopping the feeding when the prescribed grinding has been performed, a control mechanism including a bracket, a bushing journaled in the bracket, a rock shaft journaled in the bushing, a yoke carried by the bushing and slidable therewith, a pressure roller carried by the yoke for exterior engagement with a work piece when in position in engagement with the work rest and regulating wheel, means for urging the roller into engagement with the work, an ejector pivotally supported by the yoke, means for shifting the yoke to disengage the roller from the work and for shifting the ejector relative to the yoke to remove the Work piece from the machine, a cam member carried by the rock shaft and meansactuable by the cam for reversing the direction of movement of the shaft.

14. In a machine of the character described the combination with a bed and a grinding wheel carried thereby, of a work supporting unit mounted on the bed including a work rest and opposed regulating wheel for peripheral engagement with the exterior of the work, means for imparting relative axial movement to the grinding wheel and Work supporting mechanism, means for imparting relative feeding movement to said parts, a gaging device, connections between the gaging device and the feeding mechanism for stopping the feeding when the prescribed grinding has been performed, a control mechanism including a. bracket, a bushing journaled in the bracket, a rock shaft journaled in the bushing, a yoke carried by the bushing and slidable therewith, a pressure roller carried by the yoke for exterior engagement with a work piece when in position in engagement with the work piece when in position in engagement with the work rest and regulating wheel, means for urging the roller into engagement with the work, an ejector pivotally supported by the yoke, means for shifting the yoke to disengage the roller from the work and for shifting the ejector relative to the yoke to remove the work piece from the machine, a cam carried by the rock shaft and means actuable by movement of the cam for initiating movement of the work holding unit as an entirety.

15. In a grinding machine, a grinding member and a work supporting member, means to procure a relative axial movement between said members to bring said members into operative relation, means to procure a transverse movement of one of said members for a relative radial movement therebetween, a gauge contacting with the surface of a work piece in said work supporting member, means responsive to operation of said gauge to reverse the transverse movement of the member and to procure axial separation of said members, and an ejector for procuring a radial discharge of said work piece 

